This will be the “Diner des Tsars”, a sumptuous banquet that will take place in London next month: tickets are £1,500 a pop before you even think about the Louis Roederer Cristal champagne at £1,200 a jeroboam. In the Great Hall guests will tuck into an eight-course banquet prepared by the Michelin-starred chef Tom Aikens. Caviar with avocado purée, lobster and artichoke salad, poached turbot with langoustine sauce and chervil gnocchi and many more delicacies are on the menu.It is a feast fit for a tsar — which is exactly what it was 140 years ago. The Guildhall event is a recreation of a gut-busting blow-out staged in 1867 by Tsar Alexander II, Tsarevich Alexander and Kaiser Wilhelm I in Paris.It is also a sign of these extraordinary times. This is the elite of a new empire at play, and a solid gold bookmark in the annals of indulgence. Imperial fortunes are once again being made almost overnight, not in the mines of far-flung colonies, but on the trading screens of global banks and the boardrooms of private equity powerhouses. And the epicentre of this plutocracy is London.